After doing a short Super Search for Excel.Application, some good posts showed up and I think I know where your problem is. First, the error reporting is done through Win32::OLE::Error or something like that, unless you have a line Win32::OLE->Option( Warn => 3 ); or something similar.

#!perl -w
use strict;
use Win32::OLE qw(with in);
Win32::OLE->Option( Warn => 3 );

my $app = Win32::OLE->new('Excel.Application','Quit');
$app->visible();
my $workbook = $app->Workbooks->Add();
my $sheet=$workbook->Worksheets(1);
my $range=$sheet->Range('E1');
$sheet->Columns($range)->ColumnWidth(1);

sub Quit {
  $app->close;
};
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With this code, I get some error about "Columns", but I'm too lazy to investigate why Excel dosen't like it or whether this is the normal way to go about resizing columns.